Properties of eka aluminium matches well with:

Options

A. Sodium
B. Potassium
C. Magnesium
D. Gallium

Answer

To solve the question regarding which element's properties match well with eka-aluminium, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the term "eka-aluminium":**
- Eka-aluminium is a term coined by Mendeleev in 1871 for an element that he predicted would have properties similar to aluminium.

2. **Identify the options given:**
- The options provided are:
1. Sodium
2. Potassium
3. Magnesium
4. Gallium

3. **Recall the properties of aluminium:**
- Aluminium is known for its lightweight, low density, and specific chemical properties, including its oxides and chlorides.

4. **Analyze the options:**
- Sodium and potassium are alkali metals and have different properties compared to aluminium.
- Magnesium is a metal but is in the same group as aluminium and has some similar properties, but not as closely related as gallium.
- Gallium is in the same group (Group 13) as aluminium in the periodic table and was discovered after aluminium.

5. **Match the properties:**
- Gallium (Ga) has similar properties to aluminium (Al), such as:
- Atomic mass
- Density
- Melting point
- Chemical behavior (similar formulas for oxides and chlorides)

6. **Conclusion:**
- Based on the analysis, the properties of eka-aluminium match well with gallium. Therefore, the correct answer is option 4: Gallium.

### Final Answer:
The properties of eka-aluminium match well with **Gallium** (Option 4).

---